(Reuters) - Viacom Inc <VIAB.O>, the owner of Comedy Central, Nickelodeon and MTV, is in talks to acquire Argentine broadcaster Television Federal SA from phone carrier Telefonica SA <TEF.MC> for up to $385 million, according to people familiar with the deal.

The deal could be announced as soon as this week, said one of the people, all of whom wished to remain anonymous because the talks are still confidential. The deal will require regulatory approval, another of the people said.

A Viacom spokesman declined to comment. A request for comment to Telefonica SA was not immediately returned.

The deal comes as the controlling shareholders of Viacom and CBS Corp <CBS.N>, Sumner and Shari Redstone, have asked the two companies to consider merging. Both companies have created special committees of their directors to explore the matter.

Viacom's international business has been a bright spot for the company that has been struggling to turn around declining ad revenue and ratings. On Monday, Viacom named Bob Bakish, the head of its international business, as interim chief executive, effective Nov. 15.

Bloomberg first reported news of the deal.

(Reporting By Jessica Toonkel in New York, Additional reporting by Nicolas Misculin in Buenos Aires; Editing by Meredith Mazzilli)